1. Field of the Invention
The present invention relates to magnetic laminations for use, for example, in magnetic heads or sensors, and more particularly to the lamination of magnetically hard and magnetically soft films alternately superposed in units of one or more or a lamination of at least one hard magnetic film and a magnetically soft multi-layer or a magnetically soft artificial lattice lamination.
2. Discussion of Related Art
Since a magnetically soft material such as a Ni--Fe alloy (permalloy) is capable of sensing a change in a weak magnetic field electrically, it can be used as a material of a magnetic head or a magnetic sensor. Research into and development of such materials have been made in many fields.
In order to improve the performance of an MR (Magneto Resistor) device using a magnetic lamination, research into and development of materials having higher magnetic sensitivity than the conventional one are demanded. As a result, a so-called giant magnetoresistive effect has recently been discovered in artificial lattice films of Fe/Cr or Co/Cu.
However, in the conventional artificial lattice films, no materials having sufficiently high magnetic field sensitivity (modulation degree) have been discovered, the main reason of which is that film thickness conditions are selected, where an antiferromagnetic combination occurs between adjacent magnetic films, in order to realize a so-called antiferromagnetic disposition where the directions of magnetization of adjacent magnetic layers are reverse to each other in a stabilized state of magnetization when the external magnetic field is zero.